Sportkilt = pajamas for me, though their higher end models I might run to the store in. I would really call them formal at all.
They are excellent for competing in athletic events (as the name implies) so if you arent doing that, or kicking around the house, then I personally would not have a use for one.

UK Survivals on the other hand, are a true workhorse of a kilt. Maybe not as rugged as a Workmans model, they are very robust kilts with good fabric, lots of pockets, and they can dress up nicely. Take off the side pockets and you get a pretty nice dress kilt, or leave the pockets on and its sort of the kilt version of cargo pocket chino's.

If you want a kilt NOW, well then its an easy choice since UK doesnt have any in. Of course, if there is a festival near you odds are there is something in your size you can pick up in person, regardless of what they have in the store.